title: Lethal T- and NK-cell lymphomas mimicking granulomatous panniculitidies: a clinicopathologic study of three cases.
abstract: An infiltrate mimicking subcutaneous panniculitis associated with a granulomatous response represents an uncommon histopathologic presentation of lymphoma. We report three cases, comprising one case each of nasal-type extranodal NK/T-cell lymphoma, cutaneous γ/δ T-cell lymphoma and human T-lymphotropic virus-I associated adult T-cell leukemia/lymphoma, which based on initial histopathologic and/or clinical presentation were thought to represent systemic lupus erythematosus, sarcoidosis and psoriasiform dermatitis, respectively. Excisional biopsies of indurated lesions performed at our institute; however, in each case showed an atypical subcutaneous lymphohistiocytic infiltrate associated with a variable number of granulomas. Extensive immunophenotypic characterization, in conjunction with histomorphologic and molecular analysis, established the diagnosis of lymphoma in all instances. All patients had a rapidly progressive clinical course and death was attributable to complications of lymphoma shortly after diagnosis. These cases highlight the importance of using a multimodality diagnostic approach to distinguish lymphomas masquerading as granulomatous panniculitis from inflammatory or reactive disorders associated with such histopathologic patterns.
authors.affiliation: Department of Pathology and Cell Biology, Columbia University Medical Center and New York Presbyterian Hospital, New York, NY 10032, USA.
authors.forename: Kar Fai
authors.initials: KF
authors.lastname: Chow
authors.forename: Ellen
authors.initials: E
authors.lastname: Ritchie
authors.forename: Sameera
authors.initials: S
authors.lastname: Husain
authors.forename: Bachir
authors.initials: B
authors.lastname: Alobeid
authors.forename: Govind
authors.initials: G
authors.lastname: Bhagat
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D005260:Female; D006099:Granuloma / Q000209:etiology / Q000473:pathology*; D006801:Humans; D016130:Immunophenotyping; D008180:Lupus Erythematosus, Systemic / Q000473:pathology; D054391:Lymphoma, Extranodal NK-T-Cell / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D015434:Panniculitis / Q000209:etiology / Q000473:pathology*; D011565:Psoriasis / Q000473:pathology; D012507:Sarcoidosis / Q000473:pathology; D012878:Skin Neoplasms / Q000150:complications / Q000473:pathology*